In our experience, a Toyota Corolla (hired from another company in Windhoek) was unsuitable for the majority of gravel C roads in Namibia. After fixing a blow-out in the desert we approached Swakopmund Car Hire and booked a Ford Ranger for the rest of the trip. Excellent service by Lene and, even with the drop-off fee back at Windhoek Airport, the charges were very reasonable (but keep below the agreed km per day or it becomes very expensive). This 4x4 vehicle was clean and in great condition for crossing river beds and around Etosha Park.
Awesome experience with Swakopmund Car Hire in December 2016. Save yourself time and frustration and go directly to them. Professional team who will look after you and nothing is ever too much trouble. Will definitely recommend and use them again